Rods and Bearings

A project log for Micro Injection Molding Machine

Building a tabletop injection molding machine.

jupdykejupdyke 02/15/2016 at 03:176 Comments

So I have been looking at where to source my precision rods and bearings. I have done some other projects with linear motion so I have a little experience. I am trying to design around relatively inexpensive parts. Mcmaster is not the best source for inexpensive parts, but if you can find it on McMaster then you can find it somewhere else cheap as well.

For the rods I am thinking about these:

Hardened Precision Steel Shaft

For the bearings I am thinking about these:

Dust Resistant Linear Sleeve Bearings

I also did a little research and have been looking at standard mold design. There is a huge amount of information on injection molding and it has taken me a while to really wrap my brain around some of the aspects of the mold design. This molding machine will be too small to use a standard mold design, but some elements can be copied. I am planning on doing something similar to this design. However, I will not have a spacer blocks, and the bottom clamp plate will be combined with the support plate.


Jan wrote 02/15/2016 at 05:30 point

Did you see the clearance the bearings have? We sometimes use them and are often amazed how much space there is between them and the rod (sometimes even out of spec). The site says between 0,04 and 0,09mm. One tenth of a millimeter sounds way too much for me (in this application)?!

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ottoragam wrote 02/15/2016 at 05:07 point

Hi again, jupdyke. You could source some hardened rods from Ebay or Aliexpress. I bought some 1/2 in ones a few years ago and they were fine. They're really cheap and could allow you to make some prototypes without spending though the roof.

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Alex Rich wrote 02/16/2016 at 19:27 point

This is just wrong, so we're going to a link for hardened shaft - then every image on that page has a note in red text:  "can be cu_t any length".  Hilarious.  Those are great prices though!

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ottoragam wrote 02/16/2016 at 19:35 point

LOL nice catch, fantastic wordplay by the chinese!

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Alex Rich wrote 02/16/2016 at 19:37 point

It definitely made me double take, I was like oh nice - they'll cut it to... wait a second!

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ottoragam wrote 02/16/2016 at 19:50 point

They definitely know how to sell their stuff ;)

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